The present disclosure relates to fitting structures of a pair of cylindrical members which are fitted to each other at their respective ends with a sealing member interposed therebetween, and for example, relates to fitting structures of cylindrical members used to fit a shaft accommodating part, which is part of a vehicle's steering gear box and in which a steering shaft is inserted and accommodated, into one end of a dust cover for preventing dust from coming into the steering gear box.
In general, a vehicle includes, at a front side thereof, a dash panel which separates an engine compartment and a cabin from each other, a steering shaft which passes through an opening formed in the dash panel, a steering wheel provided at the cabin and coupled to the upper end of the steering shaft, and a steering gear box provided at the engine compartment and drive-coupled to the lower end of the steering shaft. Japanese Unexamined Patent Publication No. 10-250602 (page 3, FIG.5) discloses a column hole cover structure in which a cylindrical bush that slide-contacts with an outer circumferential surface of a steering shaft is inserted in a rubber-made column hole cover attached to a periphery of the opening in the dash panel from the cabin side. The column hole cover structure prevents water or the like from entering from the steering gear box to the cabin or from the cabin to the steering gear box.
The steering gear box includes a cylindrical shaft accommodating part which is part of the steering gear box and in which a lower end portion of the steering shaft is inserted and accommodated. In some cases, a dust cover which prevents entry of dust into the steering gear box may be attached to the shaft accommodating part. Specifically, the shaft accommodating part includes, at one end thereof, a first fitting cylinder that is fitted into the dust cover, and a recess is formed in the entire outer circumferential surface of the first fitting cylinder. On the other hand, the dust cover includes an annular flange which protrudes from one end of the dust cover in a direction orthogonal to the cylinder's center line, and a second fitting cylinder which is provided at the entire protrusion edge of the flange and projects in the cylinder's center line direction from the protrusion edge, and into which the first fitting cylinder is inserted. The first fitting cylinder is press-fitted in the second fitting cylinder, with an annular double-sided tape adhered to the flange, and an O ring fitted in the recess, wherein the double-sided tape is strongly pressed by the end of the first fitting cylinder and the flange.